Charged particle beam writing apparatus and charged particle beam writing method

Abstract

A apparatus according to an embodiment includes a unit to generate first blocks in a writing region in which at least one of writing groups respectively using different base doses is to be written, a unit to generate second blocks for proximity effect correction, in the each of the regions of the groups, a unit to calculate an area density in each of the first blocks, a unit to perform a weighting calculation on the area density for each of the first blocks by using a base dose of a corresponding group, a unit to calculate a dose coefficient for proximity effect correction, for each of the second blocks, by using a corresponding weighted area density, and a unit to calculate a dose by using the base dose of the each of the groups and the dose coefficient of the each of the second blocks.

What is claimed is: 
     
       1. A charged particle beam writing apparatus comprising:
 a first block generation unit configured to generate a plurality of area processing blocks in a writing region in which a plurality of writing groups respectively using different one of base doses set in advance, where a plurality of figure patterns are arranged in each of regions of the plurality of writing groups, is to be written; 
 a second block generation unit configured to generate a plurality of proximity effect correction processing blocks for proximity effect correction, in the each of the regions of the plurality of writing groups; 
 an area density calculation unit configured to calculate an area density of a figure pattern arranged in each of the plurality of area processing blocks; 
 a weighting calculation unit configured to perform a weighting calculation on the area density for each of the plurality of area processing blocks by using a base dose of a corresponding group in the plurality of writing groups; 
 a proximity effect correction dose coefficient calculation unit configured to calculate a proximity effect correction dose coefficient for proximity effect correction, for each of the plurality of proximity effect correction processing blocks, by using a corresponding weighted area density; 
 a dose calculation unit configured to calculate a dose of a charged particle beam by using the base dose of the each of the plurality of writing groups and the proximity effect correction dose coefficient, calculated using the corresponding weighted area density weighted by the base dose, of the each of the plurality of proximity effect correction processing blocks; and 
 a writing unit configured to write a figure pattern concerned in the plurality of figure patterns on a target object with a charged particle beam, based on the dose calculated, for the each of the regions of the plurality of writing groups. 
 
     
     
       2. The apparatus according to  claim 1 ,
 wherein the writing region includes the regions of the plurality of writing groups, and the first block generation unit generates the plurality of area processing blocks by dividing the writing region regardless of the regions of the plurality of writing groups, and 
 the area density calculation unit calculates the area density for each of the plurality of area processing blocks generated by being divided regardless of the regions of the plurality of writing groups. 
 
     
     
       3. The apparatus according to  claim 2 , further comprising:
 a proximity effect correction coefficient calculation unit configured to calculate a proximity effect correction coefficient for the each of the regions of the plurality of writing groups by using a base dose and a proximity effect correction coefficient which were set regardless of the regions of the plurality of writing groups, and a base dose of the each of the plurality of writing groups. 
 
     
     
       4. The apparatus according to  claim 1 ,
 wherein the proximity effect correction dose coefficient calculation unit calculates the proximity effect correction dose coefficient by simultaneously solving dose equations each being for the each of the regions of the plurality of writing groups. 
 
     
     
       5. The apparatus according to  claim 1 , further comprising:
 a judgment unit configured to judge whether a proximity effect correction dose coefficient at each position for a writing group currently concerned in the plurality of writing groups has already been calculated. 
 
     
     
       6. The apparatus according to  claim 5 , further comprising:
 a storage device configured to store the proximity effect correction dose coefficient; and 
 a read unit configured, in a case that the proximity effect correction dose coefficient at the each position for the writing group currently concerned in the plurality of writing groups has already been calculated, to read the proximity effect correction dose coefficient from the storage device. 
 
     
     
       7. The apparatus according to  claim 5 , further comprising:
 a judgment unit configured to judge, in a case that the proximity effect correction dose coefficient has not yet been calculated, whether the area density has already been calculated. 
 
     
     
       8. A charged particle beam writing method comprising:
 generating a plurality of area processing blocks in a writing region in which a plurality of writing groups respectively using different one of base doses set in advance, where a plurality of figure patterns are arranged in each of regions of the plurality of writing groups, is to be written; 
 generating a plurality of proximity effect correction processing blocks for proximity effect correction, in the each of the regions of the plurality of writing groups; 
 calculating an area density of a figure pattern arranged in each of the plurality of area processing blocks; 
 performing a weighting calculation on the area density for each of the plurality of area processing blocks by using a base dose of a corresponding group in the plurality of writing groups; 
 calculating a proximity effect correction dose coefficient for proximity effect correction, for each of the plurality of proximity effect correction processing blocks, by using a corresponding weighted area density; 
 calculating a dose of a charged particle beam by using the base dose of the each of the plurality of writing groups and the proximity effect correction dose coefficient, calculated using the corresponding weighted area density weighted by the base dose, of the each of the plurality of proximity effect correction processing blocks; and 
 writing a figure pattern concerned in the plurality of figure patterns on a target object with a charged particle beam, based on the dose calculated, for the each of the regions of the plurality of writing groups. 
 
     
     
       9. The method according to  claim 8 ,
 wherein the writing region includes the regions of the plurality of writing groups, and the plurality of area processing blocks are generated by dividing the writing region regardless of the regions of the plurality of writing groups, and 
 the area density is calculated for each of the plurality of area processing blocks generated by performing the dividing regardless of the regions of the plurality of writing groups. 
 
     
     
       10. The method according to  claim 9 , further comprising:
 calculating a proximity effect correction coefficient for the each of the regions of the plurality of writing groups by using a base dose and a proximity effect correction coefficient which were set regardless of the regions of the plurality of writing groups, and a base dose of the each of the regions of the plurality of writing groups. 
 
     
     
       11. The method according to  claim 8 ,
 wherein the proximity effect correction dose coefficient is calculated by simultaneously solving dose equations each being for the each of the regions of the plurality of writing groups. 
 
     
     
       12. The method according to  claim 8 , further comprising:
 judging whether a proximity effect correction dose coefficient at each position for a writing group currently concerned in the plurality of writing groups has already been calculated. 
 
     
     
       13. The method according to  claim 12 , further comprising:
 reading, in a case that the proximity effect correction dose coefficient at the each position for the writing group currently concerned in the plurality of writing groups has already been calculated, the proximity effect correction dose coefficient having been calculated from a storage device that stores the proximity effect correction dose coefficient having been calculated. 
 
     
     
       14. The method according to  claim 12 , further comprising:
 judging, in a case that the proximity effect correction dose coefficient has not yet been calculated, whether the area density has already been calculated.